1. Field of the Invention
The present invention relates to miniature circuit processing devices, such as integrated circuit wafer probers, and to test or contact heads for use therein.
2. Description of the Prior Art
The term "prior art" as used herein, or in any statement made by or for applicant, means only that any document or thing referred to as prior art bears, directly or inferentially, a date that is earlier than the effective filing date hereof. Miniature circuit processing devices and test heads for use in the same are known in the prior art. Among such miniature circuit processing devices is the Model 1034 wafer prober made and sold by Electroglas, Inc., of Menlo Park, Calif. Test heads for use in such devices, called "probe cards" in the prior art, and methods of making the same, are shown and described in U.S. Pat. No. 3,930,809, issued to Arthur Evans on Jan. 6, 1976. A method of obtaining proper probe alignment in a multiple contact environment is shown and described in U.S. Pat. No. 4,052,793, issued to Coughlin, et al., on Oct. 11, 1977. Probe means for use on such probe cards are shown and described in my U.S. Pat. No. 4,035,723, issued on July 12, 1977.
Such prior art miniature circuit processing devices and probe cards therefor, however, generally provide only a very limited number of test probes, the majority of which test probes are arrayed in a ring-shaped array.
While the limited number and relative disposition of the test probes of these prior art test heads is convenient, in that the miniature circuit processing device operator can position the probes on the surface of the miniature circuit to be tested by direct vision, i.e., through a microscope which is part of the processing device, the limited number of probes available in these prior art miniature circuit processing devices renders them inconvenient or indeed unfit for use in testing certain miniature circuits, such as monolithic integrated circuits and hybrid integrated circuits, in which the test points to be contacted are arrayed quite densely over a very small area, rather than being disposed in a ring-shaped array.
It is believed that the prior art documents listed hereinabove contain information which is or might be considered to be material to the examination of this patent application. However, no representation or admission is made that any of the above-cited documents is part of the prior art except in the sense in which the term prior art is defined hereinabove, or that no more pertinent information exists.